当前位置: X-MOL 学术Constr. Build. Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Promotion on self-healing of cracked cement paste by triethanolamine in a marine environment
Construction and Building Materials ( IF 7.4 ) Pub Date : 2020-01-17 , DOI: 10.1016/j.conbuildmat.2020.118148
Hao Liu , Haoliang Huang , Xintong Wu , Xiaobo Wang , Jie Hu , Jiangxiong Wei , Qijun Yu

In order to hinder ingress of aggressive ions from sea water via cracks efficiently, it is of great significance to realize rapid self-healing in concrete. In this study, the feasibility to promote self-healing of cracked cement paste in sea water by using triethanolamine (TEA) was investigated. To enlarge the effects of TEA, 0.5–2% (by mass of cement) TEA was added into cement pastes and it was found that TEA can dramatically enhance the self-healing efficiency in sea water conditions. In cement pastes with TEA more than 1% (by the mass of cement), the crack closure ratio can reach 100% at a healing period of 1 d in sea water, 20 times faster than a cement paste without TEA. The permeability of cracked specimen with TEA decreased by about 90% after a healing period of 2 days. At the early stage of self-healing promoted by TEA, large amounts of Mg(OH)2 was formed, accounting for about 70 wt% of the reaction products of self-healing. It is well known that TEA can not chelate with Mg2+ ions. Therefore, the large amounts of Mg(OH)2 leading to complete self-healing of cracks in a short time indicates that the promotion on self-healing by TEA was not mainly caused by the chelating action. Experimental results show that in sea water with the high concentration of Mg2+, the property of TEA to increase its surrounding OH concentration induces the formation of Mg(OH)2. This is the main mechanism of the promotion on self-healing of cracks by TEA in cement paste in sea water.



中文翻译:

三乙醇胺在海洋环境中促进裂化水泥浆的自愈

为了有效地阻止侵蚀性离子通过裂缝从海水中侵入,实现混凝土的快速自修复具有重要意义。在这项研究中,研究了使用三乙醇胺(TEA)促进海水中裂化水泥浆自愈的可行性。为了扩大TEA的效果,在水泥浆中添加了0.5–2%(按水泥质量计)的TEA,发现TEA可以显着提高海水条件下的自愈效率。在TEA含量大于1%(按水泥质量计)的水泥浆中,在海水中愈合1 d时,裂缝的闭合率可达到100%,比不含TEA的水泥浆快20倍。经过2天的修复后,TEA破裂的试样的渗透率降低了约90%。在TEA提倡的自我修复的早期阶段,形成2,约占自愈反应产物的70重量%。众所周知,TEA不能与Mg 2+离子螯合。因此,大量的Mg(OH)2会在短时间内导致裂纹完全自我修复,这表明TEA对自我修复的促进作用主要不是由螯合作用引起的。实验结果表明,在海水中有Mg的高浓度2+,TEA的属性,以增加其周围的OH -浓度诱导的Mg(OH)的形成2。这是海水中水泥浆中TEA促进裂纹自愈的主要机理。

更新日期:2020-01-17
down
wechat
bug